I think a good C-store item would be a partially-assimilated ship (or series of ships). Along with noticable efforts of assimilation by the Borg on the hull, graphically it might be a nice incentive to give a few additional benefits, like a small +Hull Repair Bonus (Borg Nanites), or a small over-all boost to subsystems (Minor Efficiency). And maybe since Starfleet simply can't remove the assimilated portions of the ship(s) in question (for whatever reason), the ship might have an innate Borg weapon of some sort. Like a Plasma Cutter, or a Borg tractor beam.
Could also be offered to KDF with partially-assimilated Klingon Ships.
C-store really shouldn't have anything in which would affect game balance, eg. borg cutters or other buffs to the ships.
However, the appearance sounds quite good.
I always tried fiddling with the pre-existing paint jobs to try and make my intrepid look assimilated to no success.
100% agreed. I always wanted that for lower-tier ships that are refitted to Tier 5 as an explanation how they are on par with a Sovereign. Borg technology. But it also would be nice for ships with liberated Borg on it.
Perhaps this could be accomplished unlocking Borg parts, or a Borg 'material' in the ship tailor when you select material, though I'd like to seem them allow me to apply it to certain sections. Or maybe simply as a 'paint' option that changes that section to a partially assimilated section.
Some sort of partially assimilated Borg ship would be cool though, yes. I don't think it has to, or necessarily should, give us any kind of game play advantage though.